1. Field of the Invention
The present invention relates in general to any equipment (e.g., farm implements or the like) which require that a plurality of hydraulic lines be coupled together for transferring a pressurized fluid from a supply source of such fluid to a point of utilization. More particularly, the present invention relates to a hydraulic coupler assembly for use in quickly and easily coupling and uncoupling such hydraulic lines together.
2. Description of the Prior Art
Many agricultural implements, such as plows, harrowers, and the like, have various components or mechanisms which must be operated by hydraulic pressure (i.e., a pressurized fluid). For example, some farm implements have various hydraulic cylinders which lower and raise the implement into and out of engagement with the ground or which cause various tool carrying arms of the implement to extend or retract. It is a customary practice to utilize the hydraulic system of the drive vehicle to which the farm implement is usually attached (e.g., a tractor or the like) as the source of pressurized fluid for the hydraulic cylinders contained on the implement. In this regard, various hydraulic supply lines are provided on both the tractor and the implement. Suitable coupling apparatus must be provided for coupling these lines together in a fluid-tight relationship.
Various hydraulic couplers have been developed for use in coupling hydraulic lines together on both farm implements and on other types of machinery. One coupler of this type is that which is manufactured by Seymour Mfg. Co. of Seymour, Indiana, and which is referred to as a hydraulic coupler assembly, Part No. 18-1608 in the July 1976, Panther III Parts Book, page 103. A coupler of the same general type is also illustrated in U.S. Pat. No. 3,710,823 to Vik.
In the above-noted coupler, a movable body member or block is usually spaced from a fixed body member or block by a spring which tends to move the two bodies apart. The movable body has a longitudinal bore which receives two opposed nipple members. Each nipple member has a ball check valve therein. One of the nipple members (e.g., a "quick-coupler" nipple member) is detachably locked in a fixed position in the movable body by a plurality of locking balls. The locking balls engage an annular groove on the nipple member and are locked therein by a locking surface on the fixed body member. The other nipple member is slidably received inside the movable body and is connected to a cam structure for reciprocating that nipple member inside the body. This cam structure allows the two nipple members to be engaged with one another to open the ball check valves therein and establish fluid flow therethrough. However, when the cam mechanism is activated to separate the nipple members, the ball check valves are closed to interrupt the fluid flow.
One disadvantage of this type of prior art hydraulic coupler has been the difficulty associated with the coupling and uncoupling of the detachable "quick-coupler" nipple members from the movable body. Assuming the hydraulic coupler assembly is in a coupled position, to uncouple the quick-coupler nipple members, the movable body has to be moved against the force of the spring towards the fixed body member until the locking surface on the fixed body allows the locking balls to move radially outwardly, thereby releasing the quick-coupling nipple member. It has previously been necessary to manually force (e.g., by hand) these two body members together to allow the quick-coupler nipple member to be removed. Under field conditions, the coupler assembly often gets jammed and/or coated with dust, grime, crop fragments, and other particulate contaminants. This contamination of the coupler assembly sometimes makes it very difficult to properly move the two body members together to allow uncoupling. Some prior art solutions to this problem comprises dust shields or the like which cover the assembly to keep the contaminating particles out of the operating components of the assembly. However, such shields have not been totally successful in preventing contamination of the coupler assembly. In any event, the need for such shields increases the cost and complexity of the hydraulic coupler assembly.
Even assuming that dust contamination can be prevented from clogging such hydraulic couplers, the spring pressure between the body members usually is sufficiently strong such that some persons (e.g., women, children, and the like) are unable to move the body members together to uncouple the quick-coupler nipple member. In this regard, many farmers customarily utilize their wives and/or their children to help in the work of the farm. A common farming practice, especially when the work that is being performed in the field takes more than one day to complete, is to simply leave the farm implement in the field in the evening while the tractor is returned to the barnyard. If a child is operating the tractor and implement, he is often not strong enough to move the body members on the coupler together to release the coupling lines between the tractor and implement. Thus, he is forced to return both the implement and the tractor to the barnyard and is not able to leave the implement out in the field at the location where the day's work was ended. Thus, when beginning work the next morning or the next time, it is necessary to return the implement to the field and reposition it as necessary to continue the farming operation.
Finally, in uncoupling prior art coupler assemblies, it is necessary to first activate the cam structure to separate the nipple members before attempting to move the body members together to uncouple the hydraulic lines. This interrupts the hydrualic pressure in the lines which somewhat eases the task of forcing the body members together. However, it also requires two separate operations for the farmer. A first operation is necessary to activate the cam structure and the second operation involves the manual pushing of the body members together to finish the job of disconnecting the quick-coupler nipple member. The need for two such separate operations increases the time needed to couple or uncouple the hydraulic coupler assembly.